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		<title>three.js webgpu - scenes transition</title>
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		<link type="text/css" rel="stylesheet" href="example.css">
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		<div id="info">
			<a href="https://threejs.org/" target="_blank" rel="noopener" class="logo-link"></a>

			<div class="title-wrapper">
				<a href="https://threejs.org/" target="_blank" rel="noopener">three.js</a><span>Scene Transitions</span>
			</div>

			<small>Original implementation by <a href="https://twitter.com/fernandojsg" target="_blank">fernandojsg</a> - <a href="https://github.com/kile/three.js-demos" target="_blank">github</a>.</small>
		</div>

		<script type="importmap">
			{
				"imports": {
					"three": "../build/three.webgpu.js",
					"three/webgpu": "../build/three.webgpu.js",
					"three/tsl": "../build/three.tsl.js",
					"three/addons/": "./jsm/"
				}
			}
		</script>

		<script type="module">

			import * as THREE from 'three/webgpu';

			import TWEEN from 'three/addons/libs/tween.module.js';

			import { Inspector } from 'three/addons/inspector/Inspector.js';

			import { uniform, pass } from 'three/tsl';
			import { transition } from 'three/addons/tsl/display/TransitionNode.js';

			let renderer, postProcessing, transitionController, transitionPass;

			const textures = [];
			const clock = new THREE.Clock();

			const effectController = {
				animateScene: true,
				animateTransition: true,
				transition: 0,
				_transition: uniform( 0 ),
				useTexture: true,
				_useTexture: uniform( 1 ),
				texture: 5,
				cycle: true,
				threshold: uniform( 0.1 ),
			};

			function generateInstancedMesh( geometry, material, count ) {

				const mesh = new THREE.InstancedMesh( geometry, material, count );

				const dummy = new THREE.Object3D();
				const color = new THREE.Color();

				for ( let i = 0; i < count; i ++ ) {

					dummy.position.x = Math.random() * 100 - 50;
					dummy.position.y = Math.random() * 60 - 30;
					dummy.position.z = Math.random() * 80 - 40;

					dummy.rotation.x = Math.random() * 2 * Math.PI;
					dummy.rotation.y = Math.random() * 2 * Math.PI;
					dummy.rotation.z = Math.random() * 2 * Math.PI;

					dummy.scale.x = Math.random() * 2 + 1;

					if ( geometry.type === 'BoxGeometry' ) {

						dummy.scale.y = Math.random() * 2 + 1;
						dummy.scale.z = Math.random() * 2 + 1;

					} else {

						dummy.scale.y = dummy.scale.x;
						dummy.scale.z = dummy.scale.x;

					}

					dummy.updateMatrix();

					mesh.setMatrixAt( i, dummy.matrix );
					mesh.setColorAt( i, color.setScalar( 0.1 + 0.9 * Math.random() ) );

				}

				return mesh;

			}

			function FXScene( geometry, rotationSpeed, backgroundColor ) {

				const camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 0.1, 100 );
				camera.position.z = 20;

				// Setup scene
				const scene = new THREE.Scene();
				scene.background = new THREE.Color( backgroundColor );
				scene.add( new THREE.AmbientLight( 0xaaaaaa, 3 ) );

				const light = new THREE.DirectionalLight( 0xffffff, 3 );
				light.position.set( 0, 1, 4 );
				scene.add( light );

				this.rotationSpeed = rotationSpeed;

				const color = geometry.type === 'BoxGeometry' ? 0x0000ff : 0xff0000;
				const material = new THREE.MeshPhongNodeMaterial( { color: color, flatShading: true } );
				const mesh = generateInstancedMesh( geometry, material, 500 );
				scene.add( mesh );

				this.scene = scene;
				this.camera = camera;
				this.mesh = mesh;

				this.update = function ( delta ) {

					if ( effectController.animateScene ) {

						mesh.rotation.x += this.rotationSpeed.x * delta;
						mesh.rotation.y += this.rotationSpeed.y * delta;
						mesh.rotation.z += this.rotationSpeed.z * delta;

					}

				};

				this.resize = function () {

					camera.aspect = window.innerWidth / window.innerHeight;
					camera.updateProjectionMatrix();

				};

			}

			const fxSceneA = new FXScene( new THREE.BoxGeometry( 2, 2, 2 ), new THREE.Vector3( 0, - 0.4, 0 ), 0xffffff );
			const fxSceneB = new FXScene( new THREE.IcosahedronGeometry( 1, 1 ), new THREE.Vector3( 0, 0.2, 0.1 ), 0x000000 );

			function init() {

				// Initialize textures

				const loader = new THREE.TextureLoader();

				for ( let i = 0; i < 6; i ++ ) {

					textures[ i ] = loader.load( 'textures/transition/transition' + ( i + 1 ) + '.png' );

				}

				renderer = new THREE.WebGPURenderer( { antialias: true } );
				renderer.inspector = new Inspector();
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				renderer.setAnimationLoop( animate );
				document.body.appendChild( renderer.domElement );

				postProcessing = new THREE.PostProcessing( renderer );

				const scenePassA = pass( fxSceneA.scene, fxSceneA.camera );
				const scenePassB = pass( fxSceneB.scene, fxSceneB.camera );

				transitionPass = transition( scenePassA, scenePassB, new THREE.TextureNode( textures[ effectController.texture ] ), effectController._transition, effectController.threshold, effectController._useTexture );

				postProcessing.outputNode = transitionPass;

				const gui = renderer.inspector.createParameters( 'Settings' );

				gui.add( effectController, 'animateScene' ).name( 'Animate Scene' );
				gui.add( effectController, 'animateTransition' ).name( 'Animate Transition' );
				transitionController = gui.add( effectController, 'transition', 0, 1, 0.01 ).name( 'transition' ).onChange( () => {

					effectController._transition.value = effectController.transition;

				} );
				gui.add( effectController, 'useTexture' ).onChange( () => {

					const value = effectController.useTexture ? 1 : 0;
					effectController._useTexture.value = value;

				} );
				gui.add( effectController, 'texture', { Perlin: 0, Squares: 1, Cells: 2, Distort: 3, Gradient: 4, Radial: 5 } );
				gui.add( effectController, 'cycle' );
				gui.add( effectController.threshold, 'value', 0, 1, 0.01 ).name( 'threshold' );

			}

			window.addEventListener( 'resize', onWindowResize );

			function onWindowResize() {

				fxSceneA.resize();
				fxSceneB.resize();
				renderer.setSize( window.innerWidth, window.innerHeight );

			}

			new TWEEN.Tween( effectController )
				.to( { transition: 1 }, 1500 )
				.onUpdate( function ( ) {

					transitionController.setValue( effectController.transition );

					// Change the current alpha texture after each transition
					if ( effectController.cycle ) {

						if ( effectController.transition == 0 || effectController.transition == 1 ) {

							effectController.texture = ( effectController.texture + 1 ) % textures.length;

						}

					}

				} )
				.repeat( Infinity )
				.delay( 2000 )
				.yoyo( true )
				.start();

			function animate() {

				if ( effectController.animateTransition ) TWEEN.update();

				if ( textures[ effectController.texture ] ) {

					const mixTexture = textures[ effectController.texture ];
					transitionPass.mixTextureNode.value = mixTexture;

				}

				const delta = clock.getDelta();
				fxSceneA.update( delta );
				fxSceneB.update( delta );

				render();

			}

			function render() {

				// Prevent render both scenes when it's not necessary
				if ( effectController.transition === 0 ) {

					renderer.render( fxSceneB.scene, fxSceneB.camera );

				} else if ( effectController.transition === 1 ) {

					renderer.render( fxSceneA.scene, fxSceneA.camera );

				} else {

					postProcessing.render();

				}

			}

			init();

		</script>
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